SOLUTION: The variable z varies jointly with x and y. Use the given values to write an equation relating x, y, and z. Then find z when x=-1 and y=4. 1) x=2, y=4, z=-2 2) x=4, y=1/2, z=-1

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Question 329501: The variable z varies jointly with x and y. Use the given values to write an equation relating x, y, and z. Then find z when x=-1 and y=4.
1) x=2, y=4, z=-2
2) x=4, y=1/2, z=-1

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
The variable z varies jointly with x and y. Use the given values to write an equation relating x, y, and z. Then find z when x=-1 and y=4.
1) x=2, y=4, z=-2
--------------
z = kxy
-2 = k*2*4
k = -1/4
--------------
Then find z when x=-1 and y=4.
z = (-1/4)*(-1)*4
z = 1

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